Session 12 - mood disorders Flashcards
what are the 2 broad classes of mood/affective disorders
- depressive disorders
- Bipolar disorders
How long do patients usually have the symptoms of depressive disorders and what are the core symptoms and some other features?
- 2 weeks
- Low mood, lack of energy, lack of enjoyment and interest
- Depressive thoughts - suicidal ideation
- Somatic symptoms/biological symptoms - lack of appetite, pain
What may patients have in severe cases of depressive disorders?
psychotic symptoms eg. Delusions
What is an adjustment reaction?
- it occurs after some kind of traumatic event and has fewer somatic features compared to depression
- These reactions don’t last as long and have a fluctuating course
What is the difference between an adjustment reaction and depression?
Which class of disorder is mania seen in?
bipolar disorder
What are the clinical features of mania?
- elated mood - they can become irritable as people aren’t able to keep up with them
- Increased energy
- Pressure of speech - speaking quickly. If you ask them a question or ask them to stop, they just ignore you or raise their voice
- Decreased need for sleep - they say that they’re sleeping well and are fine but in reality are only sleeping for a couple of hours
- Flight of ideas - racing thought
- Normal social inhibitions are lost - might do out of character actions eg. Gambling
- Attention can’t be sustained
- Self esteem is inflates (grandiose) - often grandiose - high sense of their own self worth eg. Think they can cure cancer
- May have psychotic symptoms - in keeping with their mood
How do you diagnose bipolar affective disorder?
2 episodes of a mood disorder at least one of which is mania or hypomania
What is hypomania?
the symptoms are the same as mania but don’t necessarily reach the full diagnostic criteria for mania
What is the difference between bipolar 1 and bipolar 2?
- bipolar 1 = discrete episodes of mania only or mania and depression (full manic episodes with or without depression)
- bipolar 2 = discrete episodes of hypomania or hypomania and depression
can you be diagnosed without ever having been diagnosed with depression?
yes
what does euthymia mean?
- this is the aim where a patient isn’t manic or depressed
- steady state between mania and depression
what are some physical causes of psychiatric symptoms that must be excluded?
- depression physical differentials:
- hypothyroidism
- B12 deficiency
- chronic disease eg. renal, CVS, liver failure
- anaemia
- substance misuse eg. alcohol, cannabis and stimulants
- hypoactive delirium - where a patient is inactive, has motor retardation, slowing of speech, sleepy and slow
- mania physical differentials:
- hyperthryoidism
- delirium
- iatrogenic eg. steroid induced
- infection eg. encephalitis, syphilis, HIV
- head injury
- intoxication eg with stimulates (eg. amphetamines)
which brain structures are involved in brain disorders?
- the limbic system
- frontal lobe
- basal ganglia
circuits: what is the main hypothesis of mood?
what are the functions of the frontal lobe?
- motor function
- language (Broca’s area)
- executive functions - planning, coordination activities, working through tasks with stages
- attention
- memory - feeds into limbic system
- mood
- social and moral reasoning
what are the functions of the pre frontal cortex?
- ventromedial prefrontal cortex - generation of emotions
- orbital pre frontal cortex - emotional responses - possibly via connection with the amygdala
when the pre frontal cortex doesn’t control emotions properly what effect does this have?
- it dampens the emotional response
- in severe depression it can be difficult to get them to even smile - this is a similar presentation to a front lobe brain injury
- mania - rapidly changing emotions.
what are the possible frontal lobe changes during depression and bipolar?
what are the functions of the basal ganglia?
- motor function
- psychological function - emotion, cognition, behaviour
what are some motor disorders associated with malfunction of the basal ganglia?
- parkinson’s
- wilson’s
- huntington’s
what are possible basal ganglia changes during mood disorders?
Explain which areas of the brain cause each symptom in depression and mania?
- prefrontal cortex - slowing of thought, executive dysfunction (eg. unable to get tasks completed) , altered emotional processing
- amygdala - abnormal emotional processing
- basal ganglia - impaired incentive behaviour, psychomotor changes
what are the 2 main neurotransmitters involved in mood depression?
- serotonin
- noradrenaline (norepinephrine)
- these are both monoamines
what does the monoamine hypothesis suggest?
that depressive disorder is due to abnormality in the availability of these neurotransmitters
where is serotonin produced and where is it distributed to?
- in the raphe nuclei in the brainstem
- transported to cortical areas and the limbic system
roles of serotonin?
- sleep
- impulse control
- appetite
- mood
what is the role of serotonin in depression and what is the evidence to support this?
- low in depression
- drugs that increase serotonin in brain treat depression
- 5HIAA which is a metabolite of serotonin is low in the CSF of patients with depression (esp in those who have attempted suicide)
- depletion of tryptophan which is a pre cursor serotonin causes depression
what evidence might contraindicate the involvement on serotonin in depression?
- despite the levels of serotonin rising rapidly following the use of drugs such as SSRIs, symptoms only improve over the course of weeks to months
- might be that antidepressants act to change the levels of other neurochemicals, maybe even stimulating neurogenesis in the hippo campus through growth factors such. as brain derived neurotrophic factors
where is noradrenaline produced and where is it distributed to?
- in the locus coeruleus of the brain stem (pons)
- to the cortex and limbic system
roles of noradrenaline in the brain and what can too much NA lead to?
- mood, arousal, memory, fight or flight
- too much NA → can lead to addictive behaviours eg. gambling
role of NA in depression and evidence?
- decreased in depression
- antidepressants that increase NA treat depression
- patients who have recovered form depression but still have low levels of noradrenaline are at higher risk of relapse
- post mortem studies → lower levels of noradrenaline the brains of those with depression
what are the functions of the limbic system?
- functions in emotion, memory and motivation
- it acts by influencing the endocrine system and the autonomic nervous system
- it’s evident that the limbic system is involved in depression because there’s a lack of ability to store memories and a lack of motivation
what is the main emotional circuit in this system known as and what is this circuit also responsible for?
- papez circuit
- this circuit is also responsible for memory consolidation where the hippocampus is able to induce long term potentiation in the cortex to lay down long term memory
what is the limbic system made up of?
- hippocampus
- amygdala - role in the emotional attachment of memories
- cingulate gyrus - involved in decision-making and emotional regulation
- thalamus
- hypothalamus
- basal ganglia
what are some possible changes in the limbic system during depression and bipolar?
